/*
* Portions Copyright 2000-2006 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
*
* (C) Copyright IBM Corp. 1999 All Rights Reserved.
* Copyright 1997 The Open Group Research Institute. All rights reserved.
*/
package sun.security.krb5.internal.ktab;
import sun.security.krb5.*;
import sun.security.krb5.internal.*;
import sun.security.krb5.internal.crypto.*;
import java.util.Vector;
import java.util.ArrayList;
import java.util.Arrays;
import java.io.IOException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.File;
import java.util.StringTokenizer;
/**
* This class represents key table. The key table functions deal with storing
* and retrieving service keys for use in authentication exchanges.
*
* @author Yanni Zhang
*/
public class KeyTab implements KeyTabConstants {
int kt_vno;
private static KeyTab singleton = null;
private static final boolean DEBUG = Krb5.DEBUG;
private static String name;
private Vector<KeyTabEntry> entries = new Vector<KeyTabEntry> ();
private KeyTab(String filename) throws IOException, RealmException {
init(filename);
}
public static KeyTab getInstance(String s) {
name = parse(s);
if (name == null) {
return getInstance();
}
return getInstance(new File(name));
}
/**
* Gets the single instance of KeyTab class.
* @param file the key tab file.
* @return single instance of KeyTab;
* return null if error occurs while reading data out of the file.
*/
public static KeyTab getInstance(File file) {
try {
if (!(file.exists())) {
singleton = null;
} else {
String fname = file.getAbsolutePath();
// Since this class deals with file I/O operations,
// we want only one class instance existing.
if (singleton != null) {
File kfile = new File(singleton.name);
String kname = kfile.getAbsolutePath();
if (kname.equalsIgnoreCase(fname)) {
if (DEBUG) {
System.out.println("KeyTab instance already exists");
}
}
} else {
singleton = new KeyTab(fname);
}
}
} catch (Exception e) {
singleton = null;
if (DEBUG) {
System.out.println("Could not obtain an instance of KeyTab" +
e.getMessage());
}
}
return singleton;
}
/**
* Gets the single instance of KeyTab class.
* @return single instance of KeyTab; return null if default keytab file
* does not exist, or error occurs while reading data from the file.
*/
public static KeyTab getInstance() {
try {
name = getDefaultKeyTab();
if (name != null) {
singleton = getInstance(new File(name));
}
} catch (Exception e) {
singleton = null;
if (DEBUG) {
System.out.println("Could not obtain an instance of KeyTab" +
e.getMessage());
}
}
return singleton;
}
/**
* The location of keytab file will be read from the configuration file
* If it is not specified, consider user.home as the keytab file's
* default location.
*/
private static String getDefaultKeyTab() {
if (name != null) {
return name;
} else {
String kname = null;
try {
String keytab_names = Config.getInstance().getDefault
("default_keytab_name", "libdefaults");
if (keytab_names != null) {
StringTokenizer st = new StringTokenizer(keytab_names, " ");
while (st.hasMoreTokens()) {
kname = parse(st.nextToken());
if (kname != null) {
break;
}
}
}
} catch (KrbException e) {
kname = null;
}
if (kname == null) {
String user_home =
java.security.AccessController.doPrivileged(
new sun.security.action.GetPropertyAction("user.home"));
if (user_home == null) {
user_home =
java.security.AccessController.doPrivileged(
new sun.security.action.GetPropertyAction("user.dir"));
}
if (user_home != null) {
kname = user_home + File.separator + "krb5.keytab";
}
}
return kname;
}
}
private static String parse(String name) {
String kname = null;
if (name == null) {
return null;
}
if ((name.length() >= 5) &&
(name.substring(0, 5).equalsIgnoreCase("FILE:"))) {
kname = name.substring(5);
} else if ((name.length() >= 9) &&
(name.substring(0, 9).equalsIgnoreCase("ANY:FILE:"))) {
// this format found in MIT's krb5.ini.
kname = name.substring(9);
} else if ((name.length() >= 7) &&
(name.substring(0, 7).equalsIgnoreCase("SRVTAB:"))) {
// this format found in MIT's krb5.ini.
kname = name.substring(7);
} else
kname = name;
return kname;
}
private synchronized void init(String filename)
throws IOException, RealmException {
if (filename != null) {
KeyTabInputStream kis =
new KeyTabInputStream(new FileInputStream(filename));
load(kis);
kis.close();
name = filename;
}
}
private void load(KeyTabInputStream kis)
throws IOException, RealmException {
entries.clear();
kt_vno = kis.readVersion();
if (kt_vno == KRB5_KT_VNO_1) {
kis.setNativeByteOrder();
}
int entryLength = 0;
KeyTabEntry entry;
while (kis.available() > 0) {
entryLength = kis.readEntryLength();
entry = kis.readEntry(entryLength, kt_vno);
if (DEBUG) {
System.out.println(">>> KeyTab: load() entry length: " +
entryLength + "; type: " +
(entry != null? entry.keyType : 0));
}
if (entry != null)
entries.addElement(entry);
}
}
/**
* Reads the service key from the keytab file.
* @param service the PrincipalName of the requested service.
* @return the last service key in the keytab
*/
public EncryptionKey readServiceKey(PrincipalName service) {
KeyTabEntry entry = null;
if (entries != null) {
// Find latest entry for this service that has an etype
// that has been configured for use
for (int i = entries.size()-1; i >= 0; i--) {
entry = entries.elementAt(i);
if (entry.service.match(service)) {
if (EType.isSupported(entry.keyType)) {
return new EncryptionKey(entry.keyblock,
entry.keyType,
new Integer(entry.keyVersion));
} else if (DEBUG) {
System.out.println("Found unsupported keytype (" +
entry.keyType + ") for " + service);
}
}
}
}
return null;
}
/**
* Reads all keys for a service from the keytab file that have
* etypes that have been configured for use.
* @param service the PrincipalName of the requested service
* @return an array containing all the service keys
*/
public EncryptionKey[] readServiceKeys(PrincipalName service) {
KeyTabEntry entry;
EncryptionKey key;
int size = entries.size();
ArrayList<EncryptionKey> keys = new ArrayList<EncryptionKey> (size);
if (entries != null) {
for (int i = size-1; i >= 0; i--) {
entry = entries.elementAt(i);
if (entry.service.match(service)) {
if (EType.isSupported(entry.keyType)) {
key = new EncryptionKey(entry.keyblock,
entry.keyType,
new Integer(entry.keyVersion));
keys.add(key);
if (DEBUG) {
System.out.println("Added key: " + entry.keyType +
"version: " + entry.keyVersion);
}
} else if (DEBUG) {
System.out.println("Found unsupported keytype (" +
entry.keyType + ") for " + service);
}
}
}
}
size = keys.size();
if (size == 0)
return null;
EncryptionKey[] retVal = new EncryptionKey[size];
// Sort keys according to default_tkt_enctypes
int pos = 0;
EncryptionKey k;
if (DEBUG) {
System.out.println("Ordering keys wrt default_tkt_enctypes list");
}
int[] etypes = EType.getDefaults("default_tkt_enctypes");
if (etypes == null || etypes == EType.getBuiltInDefaults()) {
// Either no supported types specified in default_tkt_enctypes
// or no default_tkt_enctypes entry at all. For both cases,
// just return supported keys in the order retrieved
for (int i = 0; i < size; i++) {
retVal[pos++] = keys.get(i);
}
} else {
for (int j = 0; j < etypes.length && pos < size; j++) {
int target = etypes[j];
for (int i = 0; i < size && pos < size; i++) {
k = keys.get(i);
if (k != null && k.getEType() == target) {
if (DEBUG) {
System.out.println(pos + ": " + k);
}
retVal[pos++] = k;
keys.set(i, null); // Cleared from consideration
}
}
}
// copy the rest
for (int i = 0; i < size && pos < size; i++) {
k = keys.get(i);
if (k != null) {
retVal[pos++] = k;
}
}
}
if (pos != size) {
throw new RuntimeException(
"Internal Error: did not copy all keys;expecting " + size +
"; got " + pos);
}
return retVal;
}
/**
* Searches for the service entry in the keytab file.
* The etype of the key must be one that has been configured
* to be used.
* @param service the PrincipalName of the requested service.
* @return true if the entry is found, otherwise, return false.
*/
public boolean findServiceEntry(PrincipalName service) {
KeyTabEntry entry;
if (entries != null) {
for (int i = 0; i < entries.size(); i++) {
entry = entries.elementAt(i);
if (entry.service.match(service)) {
if (EType.isSupported(entry.keyType)) {
return true;
} else if (DEBUG) {
System.out.println("Found unsupported keytype (" +
entry.keyType + ") for " + service);
}
}
}
}
return false;
}
public static String tabName() {
return name;
}
/**
* Adds a new entry in the key table.
* @param service the service which will have a new entry in the key table.
* @param psswd the password which generates the key.
*/
public void addEntry(PrincipalName service, char[] psswd)
throws KrbException {
EncryptionKey[] encKeys = EncryptionKey.acquireSecretKeys(
psswd, service.getSalt());
for (int i = 0; encKeys != null && i < encKeys.length; i++) {
int keyType = encKeys[i].getEType();
byte[] keyValue = encKeys[i].getBytes();
int result = retrieveEntry(service, keyType);
int kvno = 1;
if (result != -1) {
KeyTabEntry oldEntry = entries.elementAt(result);
kvno = oldEntry.keyVersion;
entries.removeElementAt(result);
kvno += 1;
} else
kvno = 1;
KeyTabEntry newEntry = new KeyTabEntry(service,
service.getRealm(),
new KerberosTime(System.currentTimeMillis()),
kvno, keyType, keyValue);
if (entries == null)
entries = new Vector<KeyTabEntry> ();
entries.addElement(newEntry);
}
}
/**
* Retrieves the key table entry with the specified service name.
* @param service the service which may have an entry in the key table.
* @return -1 if the entry is not found, else return the entry index
* in the list.
*/
private int retrieveEntry(PrincipalName service, int keyType) {
int found = -1;
KeyTabEntry e;
if (entries != null) {
for (int i = 0; i < entries.size(); i++) {
e = entries.elementAt(i);
if (service.match(e.getService()) &&
(keyType == -1 || e.keyType == keyType)) {
return i;
}
}
}
return found;
}
/**
* Gets the list of service entries in key table.
* @return array of <code>KeyTabEntry</code>.
*/
public KeyTabEntry[] getEntries() {
if (entries != null) {
KeyTabEntry[] kentries = new KeyTabEntry[entries.size()];
for (int i = 0; i < kentries.length; i++) {
kentries[i] = entries.elementAt(i);
}
return kentries;
} else {
return null;
}
}
/**
* Creates a new default key table.
*/
public synchronized static KeyTab create()
throws IOException, RealmException {
String dname = getDefaultKeyTab();
return create(dname);
}
/**
* Creates a new default key table.
*/
public synchronized static KeyTab create(String name)
throws IOException, RealmException {
KeyTabOutputStream kos =
new KeyTabOutputStream(new FileOutputStream(name));
kos.writeVersion(KRB5_KT_VNO);
kos.close();
singleton = new KeyTab(name);
return singleton;
}
/**
* Saves the file at the directory.
*/
public synchronized void save() throws IOException {
KeyTabOutputStream kos =
new KeyTabOutputStream(new FileOutputStream(name));
kos.writeVersion(kt_vno);
for (int i = 0; i < entries.size(); i++) {
kos.writeEntry(entries.elementAt(i));
}
kos.close();
}
/**
* Removes an entry from the key table.
* @param service the service <code>PrincipalName</code>.
*/
public void deleteEntry(PrincipalName service) {
int result = retrieveEntry(service, -1);
if (result != -1) {
entries.removeElementAt(result);
}
}
/**
* Creates key table file version.
* @param file the key table file.
* @exception IOException.
*/
public synchronized void createVersion(File file) throws IOException {
KeyTabOutputStream kos =
new KeyTabOutputStream(new FileOutputStream(file));
kos.write16(KRB5_KT_VNO);
kos.close();
}
public static void refresh() {
if (singleton != null) {
if (DEBUG) {
System.out.println("Refreshing Keytab");
}
singleton = null;
}
}
}